Or, at any point in an AMPL session, you can see the version message by looking at the contents of AMPL’s version option, by typing option version or print $version.

The 8-digit number represents a date in the form yyyymmdd – 30 September 2013 in this example. You can compare this date against the dates of the entries in the AMPL change logs and in the write-ups of new AMPL features.